DIGITAL COMMS QUIZ

With four bits of encoding, how many distinct symbols can be represented?

• 8

• 16

• 32

• 64

Also referred to as the symbol rate

• Bit rate

• Information capacity

• Baud rate

• Any of these

For a given bandwidth, what is the highest theoretical bit rate with binary encoding?

• Twice the bandwidth

• Half the bandwidth

• Equal to the bandwidth

• M times the bandwidth

What is the theoretical information capacity that may be propagated at a 10kHz bandwidth and if the SNR is 30dB?

• 100 kpbs

• 99 kpbs

• 50 kbps

• 49 kbps

What is theoretical information capacity that my be propagated at a 10kHz bandwidth if the system uses 64 levels of encoding?

• 120 kpbs

• 60 kpbs

• 90 kpbs

• 240 kpbs

A telephone line has a bandwidth of 3.2 kHz and a signal-to-noise ratio of 45dB. A signal is transmitted down this line using a four-level code. Calculate the maximum theoretical data rate

• 12.8 kpbs

• 42.52 kpbs

• 47.84 kpbs

• 6.4 kpbs

What is the minimum bandwidth to secure 4Mpbs transmission speed using 8-bit modulation at 27 dB SNR?

• 500 kHz

• 450 kHz

• 250 kHz

• 550 kHz

What is the minimum SNR required in a communications system with 100kHz bandwidth using 64QAM?

• 18 dB

• 24 dB

• 30 dB

• 36 dB

Which type of pulse modulation involves varying the amplitude of the carrier signal to represent binary data?

• Amplitude Modulation (AM)

• Pulse Amplitude Modulation (PAM)

• Amplitude-Shift Keying (ASK)

• Frequency-Shift Keying (FSK)

Which digital modulation technique is most resistant to noise and interference?

• Amplitude-Shift Keying (ASK)

• Frequency-Shift Keying (FSK)

• Phase-Shift Keying (PSK)

• Pulse Width Modulation (PWM)